Given below are two statements : Statement (I) : The absence of fluoride in…
2023
Given below are two statements :
Statement (I) : The absence of fluoride in drinking water causes tooth decay.
Statement (II) : Absence of fluoride in drinking water causes mottling of teeth also known as dental fluorosis.
In the light of the above statements, choose the most appropriate answer from the options given below :
- A.
Both Statement I and Statement II are correct
- B.
Both Statement I and Statement II are incorrect
- C.
Statement I is correct but Statement II is incorrect
- D.
Statement I is incorrect but Statement II is correct
Show answer & explanation
Correct answer: C
Fluoride's effect on dental health is dose-dependent rather than a simple presence-or-absence effect: adequate fluoride intake strengthens tooth enamel and lowers the risk of dental caries (tooth decay), whereas dental fluorosis — mottling or staining of the enamel — is a toxicity effect that develops from prolonged exposure to excess fluoride during tooth formation, not from a fluoride deficiency.
Applying this to the two statements here: Statement I follows the standard dose-response relationship — fluoride protects enamel against demineralization, so its absence (or an inadequate level) removes that protection and raises the risk of decay, making Statement I correct. Statement II reverses the causal direction — fluorosis results from excess fluoride exposure during enamel formation, not from its absence, so Statement II's claim about a fluoride shortfall causing mottling is incorrect.
Treating the mottling claim as true (alongside the decay-risk claim) ignores that fluorosis is documented as an excess-exposure effect, not a deficiency effect.
Treating the decay-risk claim as false discards fluoride's well-documented protective role against caries.
Treating the decay-risk claim as false while treating the mottling claim as true inverts both assessments at once.
So among the offered combinations, only the one holding the decay-risk statement true and the mottling statement false is supported by the evidence (CDC; WHO).